Interpretive Summary: Nematodes are microscopic worms that cause global crop losses exceeding $100 billion annually. Ring nematodes are one of the most economically important groups of plant-parasitic nematodes which feed on roots of many kinds of plants worldwide. A major problem with determining the extent of crop loss due to plant-parasitic nematodes is that the nematodes present in many areas are unknown. This brief report describes the discovery in Greece of one type of ring nematode called Mesocriconema xenoplax feeding on an ornamental shrub known as Viburnum. The report is the product of collaboration of ARS and the Benaki Phytopathological Institute, Greece. The results are significant because this is the first report of this damaging nematode in Greece. This report will serve as a useful guide to researchers in planning future research, identifying economically important nematode species, or determining which nematodes may be present in specific areas in Greece.

Technical Abstract:
In 2005, soil samples were collected from the rhizosphere of diseased Viburnum sp. plants growing in the back yard of a house in Kifissia, Attica, Greece. From these samples we recovered several specimens of a ring nematode that was identified as Mesocriconema xenoplax based on morphological examination and morphometric analysis of females. Photomicrographs and morphometrics of adult females are provided. The diseased plants showed symptoms of yellowing and then declining; within approximately one year all plants were dead. The diseased roots were also examined for soil pathogens and were found to be infected with fungus Rosellinia necatrix. This is the first report of M. xenoplax from Greece. Additional information regarding distribution of this nematode within the region is needed.